In the past, cartridges have been used for recording on and displaying optical recording media such as photographic movie film. The movie film is exposed one frame at a time through a light transmissive window by means of take-up and supply spools driven by motors. This type of cartridge requires the film to be held stationary under tension during exposure and feeds the film by either guide channels or springs to present a flat portion of film to the window.
Cartridges for recording on magnetic tape are usually driven at constant rates past recording and playback heads. This requires a uniform drive and in some professional sound recorders, separate motors drive the supply reel, take-up reel, and the tape drive capstan. A pinch wheel turned by a drive capstan, and guideposts are frequently used to bring magnetic tape into contact with the recording and playback heads.
European patent application Nos. 026,550 and 026,552 disclose a sealed case for tape containing optically readable information in which a wheel between two reels presses the tape against a light transmissive window for reading and writing information on the tape. The tape may have a reflective surface which is in contact with a reflective surface in the pressing wheel and data is detected through the window by path length or phase differences in reflected light from the wheel through recorded transparent data spots on the tape. The window may have the shape of a cylindrical lens for focusing the recording or reading beam on the tape. Since information is detected by phase difference, the part of the tape present behind the window must be kept in an accurately fixed position or plane with respect to the window. This critical focusing requires that the tape be stopped momentarily in that plane for writing or reading on the tape. The stopping and starting requires complex electromagnetic braking or clamping means and sensors for the tape drives. Usually only one track may be recorded on or read at one time.
It is the object of the invention to devise an optical recording tape cartridge wherein the tape may be recorded on or read during continual movement of the tape. It is another object of the invention to devise a tape cartridge in which different regions of the tape are presented at the same time to multiple reading and writing means allowing multiple recording and reading of data in different tracks and on different areas of the same track simultaneously.